These sanctions will not produce the results Washington demands, but they will hurt the economies of the US and EU, as well as Russia.
These sanctions are, according to the Obama administration, punishment for what it claims is Russia's role in the crash of Malaysia Airlines Flight 17, and for what the president claims is Russia's continued arming of separatists in eastern Ukraine. Neither of these reasons makes much sense because neither case has been proven.
The administration began blaming Russia for the downing of the plane just hours after the crash, before an investigation had even begun. The administration claimed it had evidence of Russia's involvement but refused to show it. Later, the Obama administration arranged a briefing by "senior intelligence officials" who told the media that "we don't know a name, we don't know a rank and we're not even 100 percent sure of a nationality," of who brought down the aircraft.